drivers/mtd/pic32_flash.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Copyright (C) 2015
   4  * Cristian Birsan <cristian.birsan@microchip.com>
   5  * Purna Chandra Mandal <purna.mandal@microchip.com>
   6  */
   7
   8 #include <common.h>
   9 #include <cpu_func.h>
  10 #include <dm.h>
  11 #include <fdt_support.h>
  12 #include <flash.h>
  13 #include <init.h>
  14 #include <irq_func.h>
  15 #include <asm/global_data.h>
  16 #include <linux/bitops.h>
  17 #include <mach/pic32.h>
  18 #include <wait_bit.h>
  19
  20 DECLARE_GLOBAL_DATA_PTR;
  21
  22 /* NVM Controller registers */
  23 struct pic32_reg_nvm {
  24         struct pic32_reg_atomic ctrl;
  25         struct pic32_reg_atomic key;
  26         struct pic32_reg_atomic addr;
  27         struct pic32_reg_atomic data;
  28 };
  29
  30 /* NVM operations */
  31 #define NVMOP_NOP               0
  32 #define NVMOP_WORD_WRITE        1
  33 #define NVMOP_PAGE_ERASE        4
  34
  35 /* NVM control bits */
  36 #define NVM_WR                  BIT(15)
  37 #define NVM_WREN                BIT(14)
  38 #define NVM_WRERR               BIT(13)
  39 #define NVM_LVDERR              BIT(12)
  40
  41 /* NVM programming unlock register */
  42 #define LOCK_KEY                0x0
  43 #define UNLOCK_KEY1             0xaa996655
  44 #define UNLOCK_KEY2             0x556699aa
  45
  46 /*
  47  * PIC32 flash banks consist of number of pages, each page
  48  * into number of rows and rows into number of words.
  49  * Here we will maintain page information instead of sector.
  50  */
  51 flash_info_t flash_info[CONFIG_SYS_MAX_FLASH_BANKS];
  52 static struct pic32_reg_nvm *nvm_regs_p;
  53
  54 static inline void flash_initiate_operation(u32 nvmop)
  55 {
  56         /* set operation */
  57         writel(nvmop, &nvm_regs_p->ctrl.raw);
  58
  59         /* enable flash write */
  60         writel(NVM_WREN, &nvm_regs_p->ctrl.set);
  61
  62         /* unlock sequence */
  63         writel(LOCK_KEY, &nvm_regs_p->key.raw);
  64         writel(UNLOCK_KEY1, &nvm_regs_p->key.raw);
  65         writel(UNLOCK_KEY2, &nvm_regs_p->key.raw);
  66
  67         /* initiate operation */
  68         writel(NVM_WR, &nvm_regs_p->ctrl.set);
  69 }
  70
  71 static int flash_wait_till_busy(const char *func, ulong timeout)
  72 {
  73         int ret = wait_for_bit_le32(&nvm_regs_p->ctrl.raw,
  74                                     NVM_WR, false, timeout, false);
  75
  76         return ret ? ERR_TIMEOUT : ERR_OK;
  77 }
  78
  79 static inline int flash_complete_operation(void)
  80 {
  81         u32 tmp;
  82
  83         tmp = readl(&nvm_regs_p->ctrl.raw);
  84         if (tmp & NVM_WRERR) {
  85                 printf("Error in Block Erase - Lock Bit may be set!\n");
  86                 flash_initiate_operation(NVMOP_NOP);
  87                 return ERR_PROTECTED;
  88         }
  89
  90         if (tmp & NVM_LVDERR) {
  91                 printf("Error in Block Erase - low-vol detected!\n");
  92                 flash_initiate_operation(NVMOP_NOP);
  93                 return ERR_NOT_ERASED;
  94         }
  95
  96         /* disable flash write or erase operation */
  97         writel(NVM_WREN, &nvm_regs_p->ctrl.clr);
  98
  99         return ERR_OK;
 100 }
 101
 102 /*
 103  * Erase flash sectors, returns:
 104  * ERR_OK - OK
 105  * ERR_INVAL - invalid sector arguments
 106  * ERR_TIMEOUT - write timeout
 107  * ERR_NOT_ERASED - Flash not erased
 108  * ERR_UNKNOWN_FLASH_VENDOR - incorrect flash
 109  */
 110 int flash_erase(flash_info_t *info, int s_first, int s_last)
 111 {
 112         ulong sect_start, sect_end, flags;
 113         int prot, sect;
 114         int rc;
 115
 116         if ((info->flash_id & FLASH_VENDMASK) != FLASH_MAN_MCHP) {
 117                 printf("Can't erase unknown flash type %08lx - aborted\n",
 118                        info->flash_id);
 119                 return ERR_UNKNOWN_FLASH_VENDOR;
 120         }
 121
 122         if ((s_first < 0) || (s_first > s_last)) {
 123                 printf("- no sectors to erase\n");
 124                 return ERR_INVAL;
 125         }
 126
 127         prot = 0;
 128         for (sect = s_first; sect <= s_last; ++sect) {
 129                 if (info->protect[sect])
 130                         prot++;
 131         }
 132
 133         if (prot)
 134                 printf("- Warning: %d protected sectors will not be erased!\n",
 135                        prot);
 136         else
 137                 printf("\n");
 138
 139         /* erase on unprotected sectors */
 140         for (sect = s_first; sect <= s_last; sect++) {
 141                 if (info->protect[sect])
 142                         continue;
 143
 144                 /* disable interrupts */
 145                 flags = disable_interrupts();
 146
 147                 /* write destination page address (physical) */
 148                 sect_start = CPHYSADDR(info->start[sect]);
 149                 writel(sect_start, &nvm_regs_p->addr.raw);
 150
 151                 /* page erase */
 152                 flash_initiate_operation(NVMOP_PAGE_ERASE);
 153
 154                 /* wait */
 155                 rc = flash_wait_till_busy(__func__,
 156                                           CONFIG_SYS_FLASH_ERASE_TOUT);
 157
 158                 /* re-enable interrupts if necessary */
 159                 if (flags)
 160                         enable_interrupts();
 161
 162                 if (rc != ERR_OK)
 163                         return rc;
 164
 165                 rc = flash_complete_operation();
 166                 if (rc != ERR_OK)
 167                         return rc;
 168
 169                 /*
 170                  * flash content is updated but cache might contain stale
 171                  * data, so invalidate dcache.
 172                  */
 173                 sect_end = info->start[sect] + info->size / info->sector_count;
 174                 invalidate_dcache_range(info->start[sect], sect_end);
 175         }
 176
 177         printf(" done\n");
 178         return ERR_OK;
 179 }
 180
 181 int page_erase(flash_info_t *info, int sect)
 182 {
 183         return 0;
 184 }
 185
 186 /* Write a word to flash */
 187 static int write_word(flash_info_t *info, ulong dest, ulong word)
 188 {
 189         ulong flags;
 190         int rc;
 191
 192         /* read flash to check if it is sufficiently erased */
 193         if ((readl((void __iomem *)dest) & word) != word) {
 194                 printf("Error, Flash not erased!\n");
 195                 return ERR_NOT_ERASED;
 196         }
 197
 198         /* disable interrupts */
 199         flags = disable_interrupts();
 200
 201         /* update destination page address (physical) */
 202         writel(CPHYSADDR(dest), &nvm_regs_p->addr.raw);
 203         writel(word, &nvm_regs_p->data.raw);
 204
 205         /* word write */
 206         flash_initiate_operation(NVMOP_WORD_WRITE);
 207
 208         /* wait for operation to complete */
 209         rc = flash_wait_till_busy(__func__, CONFIG_SYS_FLASH_WRITE_TOUT);
 210
 211         /* re-enable interrupts if necessary */
 212         if (flags)
 213                 enable_interrupts();
 214
 215         if (rc != ERR_OK)
 216                 return rc;
 217
 218         return flash_complete_operation();
 219 }
 220
 221 /*
 222  * Copy memory to flash, returns:
 223  * ERR_OK - OK
 224  * ERR_TIMEOUT - write timeout
 225  * ERR_NOT_ERASED - Flash not erased
 226  */
 227 int write_buff(flash_info_t *info, uchar *src, ulong addr, ulong cnt)
 228 {
 229         ulong dst, tmp_le, len = cnt;
 230         int i, l, rc;
 231         uchar *cp;
 232
 233         /* get lower word aligned address */
 234         dst = (addr & ~3);
 235
 236         /* handle unaligned start bytes */
 237         l = addr - dst;
 238         if (l != 0) {
 239                 tmp_le = 0;
 240                 for (i = 0, cp = (uchar *)dst; i < l; ++i, ++cp)
 241                         tmp_le |= *cp << (i * 8);
 242
 243                 for (; (i < 4) && (cnt > 0); ++i, ++src, --cnt, ++cp)
 244                         tmp_le |= *src << (i * 8);
 245
 246                 for (; (cnt == 0) && (i < 4); ++i, ++cp)
 247                         tmp_le |= *cp << (i * 8);
 248
 249                 rc = write_word(info, dst, tmp_le);
 250                 if (rc)
 251                         goto out;
 252
 253                 dst += 4;
 254         }
 255
 256         /* handle word aligned part */
 257         while (cnt >= 4) {
 258                 tmp_le = src[0] | src[1] << 8 | src[2] << 16 | src[3] << 24;
 259                 rc = write_word(info, dst, tmp_le);
 260                 if (rc)
 261                         goto out;
 262                 src += 4;
 263                 dst += 4;
 264                 cnt -= 4;
 265         }
 266
 267         if (cnt == 0) {
 268                 rc = ERR_OK;
 269                 goto out;
 270         }
 271
 272         /* handle unaligned tail bytes */
 273         tmp_le = 0;
 274         for (i = 0, cp = (uchar *)dst; (i < 4) && (cnt > 0); ++i, ++cp) {
 275                 tmp_le |= *src++ << (i * 8);
 276                 --cnt;
 277         }
 278
 279         for (; i < 4; ++i, ++cp)
 280                 tmp_le |= *cp << (i * 8);
 281
 282         rc = write_word(info, dst, tmp_le);
 283 out:
 284         /*
 285          * flash content updated by nvm controller but CPU cache might
 286          * have stale data, so invalidate dcache.
 287          */
 288         invalidate_dcache_range(addr, addr + len);
 289
 290         printf(" done\n");
 291         return rc;
 292 }
 293
 294 void flash_print_info(flash_info_t *info)
 295 {
 296         int i;
 297
 298         if (info->flash_id == FLASH_UNKNOWN) {
 299                 printf("missing or unknown FLASH type\n");
 300                 return;
 301         }
 302
 303         switch (info->flash_id & FLASH_VENDMASK) {
 304         case FLASH_MAN_MCHP:
 305                 printf("Microchip Technology ");
 306                 break;
 307         default:
 308                 printf("Unknown Vendor ");
 309                 break;
 310         }
 311
 312         switch (info->flash_id & FLASH_TYPEMASK) {
 313         case FLASH_MCHP100T:
 314                 printf("Internal (8 Mbit, 64 x 16k)\n");
 315                 break;
 316         default:
 317                 printf("Unknown Chip Type\n");
 318                 break;
 319         }
 320
 321         printf("  Size: %ld MB in %d Sectors\n",
 322                info->size >> 20, info->sector_count);
 323
 324         printf("  Sector Start Addresses:");
 325         for (i = 0; i < info->sector_count; ++i) {
 326                 if ((i % 5) == 0)
 327                         printf("\n   ");
 328
 329                 printf(" %08lX%s", info->start[i],
 330                        info->protect[i] ? " (RO)" : "     ");
 331         }
 332         printf("\n");
 333 }
 334
 335 unsigned long flash_init(void)
 336 {
 337         unsigned long size = 0;
 338         struct udevice *dev;
 339         int bank;
 340
 341         /* probe every MTD device */
 342         for (uclass_first_device(UCLASS_MTD, &dev); dev;
 343              uclass_next_device(&dev)) {
 344                 /* nop */
 345         }
 346
 347         /* calc total flash size */
 348         for (bank = 0; bank < CONFIG_SYS_MAX_FLASH_BANKS; ++bank)
 349                 size += flash_info[bank].size;
 350
 351         return size;
 352 }
 353
 354 static void pic32_flash_bank_init(flash_info_t *info,
 355                                   ulong base, ulong size)
 356 {
 357         ulong sect_size;
 358         int sect;
 359
 360         /* device & manufacturer code */
 361         info->flash_id = FLASH_MAN_MCHP | FLASH_MCHP100T;
 362         info->sector_count = CONFIG_SYS_MAX_FLASH_SECT;
 363         info->size = size;
 364
 365         /* update sector (i.e page) info */
 366         sect_size = info->size / info->sector_count;
 367         for (sect = 0; sect < info->sector_count; sect++) {
 368                 info->start[sect] = base;
 369                 /* protect each sector by default */
 370                 info->protect[sect] = 1;
 371                 base += sect_size;
 372         }
 373 }
 374
 375 static int pic32_flash_probe(struct udevice *dev)
 376 {
 377         void *blob = (void *)gd->fdt_blob;
 378         int node = dev_of_offset(dev);
 379         const char *list, *end;
 380         const fdt32_t *cell;
 381         unsigned long addr, size;
 382         int parent, addrc, sizec;
 383         flash_info_t *info;
 384         int len, idx;
 385
 386         /*
 387          * decode regs. there are multiple reg tuples, and they need to
 388          * match with reg-names.
 389          */
 390         parent = fdt_parent_offset(blob, node);
 391         fdt_support_default_count_cells(blob, parent, &addrc, &sizec);
 392         list = fdt_getprop(blob, node, "reg-names", &len);
 393         if (!list)
 394                 return -ENOENT;
 395
 396         end = list + len;
 397         cell = fdt_getprop(blob, node, "reg", &len);
 398         if (!cell)
 399                 return -ENOENT;
 400
 401         for (idx = 0, info = &flash_info[0]; list < end;) {
 402                 addr = fdt_translate_address((void *)blob, node, cell + idx);
 403                 size = fdt_addr_to_cpu(cell[idx + addrc]);
 404                 len = strlen(list);
 405                 if (!strncmp(list, "nvm", len)) {
 406                         /* NVM controller */
 407                         nvm_regs_p = ioremap(addr, size);
 408                 } else if (!strncmp(list, "bank", 4)) {
 409                         /* Flash bank: use kseg0 cached address */
 410                         pic32_flash_bank_init(info, CKSEG0ADDR(addr), size);
 411                         info++;
 412                 }
 413                 idx += addrc + sizec;
 414                 list += len + 1;
 415         }
 416
 417         /* disable flash write/erase operations */
 418         writel(NVM_WREN, &nvm_regs_p->ctrl.clr);
 419
 420 #if (CONFIG_SYS_MONITOR_BASE >= CONFIG_SYS_FLASH_BASE)
 421         /* monitor protection ON by default */
 422         flash_protect(FLAG_PROTECT_SET,
 423                       CONFIG_SYS_MONITOR_BASE,
 424                       CONFIG_SYS_MONITOR_BASE + monitor_flash_len - 1,
 425                       &flash_info[0]);
 426 #endif
 427
 428 #ifdef CONFIG_ENV_IS_IN_FLASH
 429         /* ENV protection ON by default */
 430         flash_protect(FLAG_PROTECT_SET,
 431                       CONFIG_ENV_ADDR,
 432                       CONFIG_ENV_ADDR + CONFIG_ENV_SECT_SIZE - 1,
 433                       &flash_info[0]);
 434 #endif
 435         return 0;
 436 }
 437
 438 static const struct udevice_id pic32_flash_ids[] = {
 439         { .compatible = "microchip,pic32mzda-flash" },
 440         {}
 441 };
 442
 443 U_BOOT_DRIVER(pic32_flash) = {
 444         .name   = "pic32_flash",
 445         .id     = UCLASS_MTD,
 446         .of_match = pic32_flash_ids,
 447         .probe  = pic32_flash_probe,
 448 };